The use of erasable boards for presentation is known. Such boards include the well known chalkboards, such as blackboards and greenboards. Also known are more recent types which have a white surface which can be marked on by a removable color marker.
A store show window having movable boards is shown in U.S. Pat. No. 1,836,960 to Elias. In this patent, a plurality of display boards are independently suspended from tracks using trolleys.
A portable rostrum is shown in U.S. Pat. No. 3,531,898 to Facemire. In this patent, a plurality of display boards are suspended for sliding along a track. The boards are in overlying relation.
In U.S. Pat. No. 3,914,890 to Behlen, Jr., a vertically moveable multi-panel sign is disclosed. A plurality of display panels or signs are mountable within tracks formed in parallel upstanding side posts. The signs include gripping apertures in their upper portions to permit removable of the signs upwardly between the side posts.
A structure having a movable panel is shown in U.S. Pat. No. 4,716,693 to Webster. The structure includes details of roller assemblies used for movably supporting a sign or panel along a track.
A carrying and display case is shown in U.S. Pat. No. 4,746,009 to Liberman. The carrying and display case includes a pair of side panels having tracks therein for removably receiving a plurality of boards. The boards bear indicia to convey information, and also support product samples.
A markerboard is shown in U.S. Pat. No. 5,035,626 to Persing. The markerboard has a frame including side members supporting the markerboard, and is suitable for use in an office environment.
A display wall assembly is shown in U.S. Pat. No. 5,067,287 to Lewis. The assembly includes a front portion, a display area, and a slidable display panel which is movable from behind part of the front portion into the display area.
A sign assembly is shown in U.S. Pat. No. 5,088,221 to Bussiere et al. In this patent, the sign assembly includes a plurality of horizontally disposed tracks for support a plurality of horizontally slidable interchangeable signs. Each of the horizontally slidable interchangeable signs has a plurality of vertical channels for receiving respective ones of a plurality of panels bearing letters.
A portable free-standing visual aid is shown in U.S. Pat. No. 5,163,845 to Blassingame. In this patent, a case includes a chalkboard on one side thereof, and a slot for receiving a display board therein. The display board is removable from the case and can be slid in front of the chalkboard.
A reusable bulletin board display is shown in U.S. Pat. No. 5,622,504 to Hance. In this patent, a first display surface is mounted within a rigid frame, and a second display surface is detachably connected to overlie the first display surface using hook-and-loop fasteners.